Cage nut

Abstract

The invention relates to a cage nut (15) for connection to a support element (1), in particular a sheet-metal part of a vehicle body, said cage nut comprising a screw nut (11) which is positioned with room for movement captively and / or non-rotatably in a nut cage (13) which can be fastened to the support element (1), wherein the screw nut (11) can be displaced between axial stops (17, 19) when not screwed, and wherein at least one spacer (33) is formed on the screw nut end face (23) that is close to an axial stop (17, 19), said spacer allowing the screw nut (11) to be brought into contact with the axial stop (17, 19), which makes it possible to reduce adhesive forces between the screw nut (11) and the axial stop (17, 19) of the nut cage (13). According to the invention, the spacer (33) is manufactured in a forming process in which the screw nut (11) can be deformed to produce the spacer (33).

Description

[0001] Cage nut

[0002] DESCRIPTION:

[0003] The invention relates to a cage nut according to the preamble of claim 1 and to a method for producing such a cage nut according to claim 10.

[0004] Cage nuts are used, among other things, for fastening tolerance-critical components to the body (e.g., for the seat, door lock, or battery housing, etc.). These nuts come in a wide variety of thread sizes and usually consist of a square steel element into which the respective thread (or even just a hole for a self-tapping screw) is inserted. This steel element, in turn, is located in a so-called nut cage, in which it is embedded in a way that prevents it from being lost and twisting.

[0005] Once the nut cage, including the nut inside, is welded into the body, a component can be screwed together later during assembly with relatively large tolerances without the use of a counter-fixture to absorb the torque during screwing. The nut is located by a screw with a threading point, so that the nut automatically centers itself to the screw, enabling process-reliable screwing despite component tolerances.

[0006] With a conventional cage nut, the following problem arises in vehicle manufacturing plants: The nut cage is welded during body shop production and therefore passes through the paint shop, including cathodic dip painting, together with the body. Depending on its position in the vehicle, the screw nut in the nut cage adheres more or less closely to the body panel or the nut cage. This is due to the fact that the extremely thin cathodic dip paint spreads everywhere, including between the screw nut and the mating surface. It does not run off there due to adhesive forces, and then cakes between them during drying in the subsequent curing oven. However, in order for the screw nut to fulfill its actual function, it must first be loosened by applying force.Depending on the type of subsequent screw connection, this can (but does not have to) be achieved, for example, by an automated screwing device based on the pressure applied to the screw when the threading tip is inserted into the screw hole of the nut. However, this does not work with manual screwing, so the operator must first release the nut from its adhesive bond by applying force, for example, with a hammer blow.

[0007] Cage nut arrangements are known from DE 11 2017 008 057 T5, from US 2004 / 0013492 A1 and from JP 2014001839 A2.

[0008] The object of the invention is to provide a cage nut and a method for producing a cage nut in which, in comparison to the prior art, a reliable function of the cage nut can be ensured in a simple process-technical manner.

[0009] The object is achieved by the features of claim 1 or 10. Preferred developments of the invention are disclosed in the subclaims.

[0010] The invention relates to a cage nut for connection to a supporting element, in particular a body sheet metal part. The cage nut has a screw nut and a nut cage which can be fixedly fastened to the supporting element, in particular by a welded connection. In the cage interior, the screw nut is arranged in a captive and rotationally secure manner with play in a non-use position, so that the screw nut can be displaced by an axial path between axial stops in a screwing direction. In a use position, the screw nut is screwed to a screw bolt, by means of which an attachment can be clamped to the supporting element. To avoid an adhesive connection occurring in the non-use position (for example, after the cathodic dip-coating process in vehicle production) between the screw nut and at least one axial stop of the nut cage, large contact surfaces between the screw nut and the cage axial stop are omitted.Instead, at least one spacer is formed on the screw nut end face facing the axial stop, which protrudes from the screw nut end face. The screw nut end face can be brought into contact with the axial stop via the spacer. The spacer has a significantly reduced cross-section compared to the screw nut end face, whereby an adhesive connection that occurs in the non-use position between the screw nut and the cage axial stop (after the cathodic dipping process) is also significantly reduced. According to the characterizing part of claim 1, the spacer on the screw nut is produced in a forming process. During the forming process, the screw nut is deformed to produce the spacer. It is preferred if, during the forming process, the forming force acts outside the screw nut end face on a circumferential screw nut edge.In this way, the screw nut faces remain free from mechanical interference during the forming process. Furthermore, it is preferred if at least one spacer is formed on each of the screw nut faces.

[0011] According to the invention, by introducing transverse embossing on the outer edge of the screw nut during production, very small, sharp burrs can be created by material displacement on the contact surface, on which the screw nut rests within the nut cage. The cathodic dip coating between the screw nut and nut cage can therefore run off after the dipping process, so that the two surfaces do not stick together. In a simple technical implementation, the forming process can be a stamping process in which at least one embossing is introduced into the screw nut. The embossing is preferably positioned at least in the vicinity of the screw nut face. This causes a material flow during the stamping process, whereby the screw nut face bulges up by one profile height to form the spacer.

[0012] According to a first embodiment, the embossing may not be formed directly in the screw nut end face, but rather be formed with an axial offset to the screw nut end face in the screw nut edge side. The screw nut may have a polygonal profile with profile edges extending between the screw nut end faces. The profile edges converge with edge edges at the screw nut's outer corners. At the edge edges, the respective screw nut end face merges into the screw nut edge side. With a view to a technically simple embossing process, it is preferred if the embossing is formed on at least one profile edge in such a way that the embossing interrupts the edge profile of the profile edge. It has been shown that when forming the embossing on the profile edge, a reduced forming force is sufficient, compared to forming the embossing on a flat edge side.Alternatively, the embossing can also be positioned outside the profile edges, i.e. arranged in the circumferential direction at a distance from the profile edges.

[0013] In a further embodiment, the stamping process can be performed directly on the outer corner of the nut, where an axially extending nut profile edge converges with transversely extending nut edges. In this case, the stamping is formed directly on the outer corner of the nut.

[0014] In a further design variant, the embossing can be positioned on the nut edge in such a way that the adjacent edge of the nut no longer extends linearly, but rather is curved to form the spacer. In this case, the edge is not interrupted by the embossing. Alternatively, the embossing can also be formed directly on the edge, so that the edge is interrupted by the embossing. From a manufacturing perspective, it is simple if the embossing extends continuously, for example in the shape of a groove, between the two axial end faces of the nut. In this way, the spacers on both end faces of the nut are produced simultaneously using exactly one embossing tool and in a single embossing process.

[0015] Embodiments of the invention are described below with reference to the attached figures.

[0016] They show:

[0017] Fig. 1 and 2 the cage nut in a non-use position and in a use position; and

[0018] Fig. 3 to 7 each show views of the cage nut in different embodiments.

[0019] In Figure 1, a sheet metal body part 1 of a vehicle body has a screw point 3. On the upper side of the sheet metal body part 1, an add-on part 5, for example a vehicle rear seat, is screwed to the screw point 3 via a screw bolt 7. In Figure 1, the screw bolt 7 is guided through a screw hole 9 in the sheet metal body part 1 and is in threaded engagement with a screw nut 11, which is arranged on the side of the sheet metal body part 1 opposite the add-on part 5. The screw nut 11, together with a nut cage 13, is part of a cage nut 15, which is shown in Figure 1 in the screwed state. The nut cage 13 is welded to the sheet metal body part 1. In contrast, the cage nut 15 is shown in Figure 2 in the unscrewed state, in which the screw nut 11 is mounted floating with play in a cage interior of the nut cage 13.According to Figures 1 and 2, the nut cage 13 has axial stops 17, 19, between which the screw nut 11 can be displaced by an axial travel Aa in the screwing direction S (Fig. 2). Furthermore, the nut cage 15 has transverse stops, between which the screw nut 11 can be displaced over a transverse travel perpendicular to the screwing direction S.

[0020] In Figure 3, the screw nut 11 is formed with a cuboid-shaped base body 21, the axial end faces 23 of which can be brought into contact with the respective facing axial stops 17, 19 of the nut cage 15. The screw nut base body 21 has a square profile with a total of four profile edges 25. Each of the profile edges 25 converges at a screw nut outer corner 27 with edge edges 29, at which the respective screw nut end face 23 merges into a screw nut edge face 31.

[0021] In a manufacturing process in body construction, the nut cage 15, with the screw nut 11 loosely mounted within it, is welded to the body sheet metal part 1. The body sheet metal part 1 is then subjected to a cathodic dip coating process. After the cathodic dip coating process is completed, the attachment 5 is screwed to the screw point 3 of the body sheet metal part 1. In the event of extensive contact between a screw nut end face 23 and an adjacent axial stop 17, 19 of the nut cage 15, there is a risk that the screw nut 11 will stick to the adjacent axial stop 17, 19 of the nut cage 15 with the intermediate layer of the cathodic dip coating. Against this background, the screw nut 11 according to the invention has spacers 33 of small cross-section on each of its two axial end faces 23, via which the screw nut 11 can be brought into contact with the axial stops 17, 19 of the nut cage 15.

[0022] A core of the invention is that the spacers 33 are formed in the screw nut 11 in a technically simple manner by a stamping process. During the stamping process, a stamping 35 is introduced into the screw nut 11 with the aid of a stamping tool. This causes a material flow, whereby the screw nut end face 23 bulges by a profile height h in the vicinity of the stamping 35, forming the spacer 33. By way of example, in Figure 3, a stamping 35 is formed on each of the profile edges 25, which interrupts the edge profile of the profile edge 25. The stamping 35 is formed with an axial offset Az to the two screw nut end faces 23 in the screw nut profile edges 25. In this way, axially raised spacers 33 are formed directly at the outer corners 27 of the screw nut 11, which protrude from the respective screw nut end faces 23 by a profile height h.

[0023] Alternatively, in Figure 4, the embossments 35 are not formed directly in the profile edges 25, but rather with a slight axial offset from the edge edges 29 and on the flat screw nut edge sides 31. According to Figure 3, the edge edge profile is not interrupted by the embossment 35. Rather, the edge edge profile bulges upwards by the profile height h, forming the spacer 33.

[0024] In Figure 5, in order to form the spacers 33, the stamping tool is directed with a forming force directly onto the respective screw nut outer corner 27, whereby a spacer 33 is built up on the respective screw nut end face 23.

[0025] In Figure 6, the embossments 35 are formed directly on the nut's peripheral edges 29, whereby the peripheral edge profile is interrupted by the embossments 35. According to Figure 6, embossments 35 are formed independently of one another on the axially opposite peripheral edges 29 of the nut base body 20. In contrast, in Figure 7, the respective embossment 35 extends in a groove-like manner and continuously between the two axial nut end faces 23. In this way, a spacer 33 is produced on each of the axial nut end faces 23 using a stamping tool and a stamping process. LIST OF REFERENCE SYMBOLS:

[0026] I Supporting element

[0027] 3 screw points

[0028] 5 Attachment

[0029] 7 screw bolts

[0030] 9 screw hole

[0031] II Screw nut

[0032] 13 Nut cage

[0033] 15 Cage nut

[0034] 17, 19 Axial stops

[0035] 21 Screw nut base body

[0036] 23 screw nut end faces

[0037] 25 profile edges

[0038] 27 screw nut outside corners

[0039] 29 Screw nut edges

[0040] 31 screw nut edges

[0041] 33 spacers

[0042] 35 Embossing h Profile height

[0043] S Screw direction

[0044] Aa axial travel

[0045] From Querweg

[0046] Az axial distance

Claims

PATENT CLAIMS:

1. Cage nut (15) for attachment to a support element (1), in particular a body panel part, comprising a screw nut (11) which is arranged in a captive and / or rotationally secure manner in a nut cage (13) that can be attached to the support element (1) and has play, wherein the screw nut (11) is displaceable between axial stops (17, 19) in the un-tightened state, and wherein at least one spacer (33) is formed on the screw nut end face (23) facing an axial stop (17, 19), via which the screw nut (11) can be brought into contact with the axial stop (17, 19), thereby in particular reducing an adhesive connection between the screw nut (11) and the axial stop (17, 19) of the nut cage (13), characterized in that the spacer (33) is manufactured in a forming process in which the screw nut (11) is The spacer (33) is deformable.

2. Cage nut according to claim 1, characterized in that the forming process takes place outside the screw nut end face (23) on a circumferential edge face (31) of the screw nut (11).

3. Cage nut according to claim 1 or 2, characterized in that the forming process is an embossing process in which at least one embossing (35) can be introduced into the screw nut (11) which causes a material flow, whereby the screw nut end face (23) bulges up in the vicinity of the embossing (35) to form the spacer (33), and / or the spacer (33) forms as a material burr.

4. Cage nut according to claim 3, characterized in that the embossing (35) is formed in the screw nut edge side (31 ) with axial offset (Az) to the screw nut end side (23). A cage nut according to one of the preceding claims, characterized in that the screw nut (11) has a polygonal profile with profile edges (25) extending between the screw nut end faces (23), and in particular that the embossing (35) is formed on at least one profile edge (25) such that the embossing (35) interrupts the edge profile of the profile edge (25). A cage nut according to claim 5, characterized in that the embossing (35) is positioned circumferentially at a distance from the profile edges (25) in the screw nut's outer face (31). A cage nut according to claim 5, characterized in that the embossing (35) is formed on at least one outer corner (27) of the screw nut (11) where the profile edge (25) terminates.Cage nut according to any one of claims 2 to 7, characterized in that the axial nut end face (23) and the nut edge face (31) converge at edge edges (29), and in particular that the edge profile is curved to form the spacer (33). Cage nut according to claim 8, characterized in that the indentation (35) is formed on the edge edge (29) such that the edge profile is interrupted by the indentation (35), and in particular that the indentation (35) extends continuously between the two axial nut end faces (23). Method for manufacturing a cage nut (15) according to any one of the preceding claims, wherein the spacer (33) is manufactured in a forming process in which the nut (11) is deformed to produce the spacer (33).

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